In explosion-prone areas, for example, on drilling rigs, the electrical energies present at the external electronic interfaces of an electronic device can ignite a gas-air mixture present in the explosion-prone area and thus cause an explosion. This applies particularly to highly reactive gas mixtures such as possibly mixtures of hydrogen and oxygen, for which said energy is available as activation energy in order to initiate an exothermic reaction possibly of hydrogen and oxygen to give water. The same applies to gas mixtures of acetylene-oxygen.
Against this background it is known from the prior art to provide pressure-resistant casings in which the electronic device to be used in the explosion-prone area can be received. It is further known to use additional damping elements in said pressure-tight casings in order to minimize the explosion pressure which develops during the ignition of the gas mixture and acts on the casing. This permits the pressure-resistant casing to be provided with thinner and therefore lighter-weight casing walls which increases the user friendliness of such a casing not inconsiderably.
Against this background DE 198 60 383 A1 discloses an electronic device in the form of a screen for an EDP system which comprises a pressure-tight casing with a transparent pane. An LCD display and an explosion pressure damping material are provided in the interior of the casing.
On the other hand, DD 261 063 A3 describes an arrangement for reducing explosion pressures in closed spaces. The arrangement comprises a casing in which an incombustible material having open continuous pores or gaps is arranged largely freely accessibly. Such a casing is fundamentally also suitable for receiving an electronic device.
The typically “soft” structure of the material which damps the explosion process proves to be problematical in such conventional casings with devices for reducing the pressure in the event of an explosion. The only low structural strength of this material can, in the event of an explosion, have the result that it is damaged or completely destroyed so that its functionality as a pressure-reducing component cannot be guaranteed with absolute certainty. This is however absolutely essential if a casing for an electronic device is to receive the certification required for use in an explosion-prone area.